Circle theorems help please

x = 75°

Step-by-step explanation:

The angle at the centre is twice the angle on the circle subtended on the same arc.

The angle at the centre is

360° - (285 - x)

= 360 - 285 + x

= 75 + x

Thus

x = (75 + x) ← multiply both sides by 2 to clear the fraction

2x = 75 + x ( subtract x from both sides )

x = 75°

v = 1/3 a^2h

step-by-step explanation:

the volume is 1/3 a^2h.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.